dyneema composite fabric simply put, Dyneema composite fabric is the highest strength-to-weight ratio fabric out there. Dyneema fibers are 30% lighter than nylon and polyester, 15x stronger than steel, uv, water, abrasion and tear resistant. we use dyneema fabric to make an ultra-light, ultra-strong version of our original 2 in 1 backpack. our 2-in-1 pack converts from 1l to 20L easily built to be adaptable